The factors of 15 are **1, 3, 5, and 15** .

Similarly, what is the common factor of Fifteen and 18? 2 and Fifteen have 18 common factors, which are **1 and 3** . Therefore, the greatest common factor of 15 and 18 is 3.

What is a factor of 21? The factors of 21 are **1, 3, 7, 21** and its negative factors are -1, -3, -7, -21.

What is the GCF of 20 and Fifteen? The GCF of Fifteen and 20 is **5** . To calculate the GCF (Greatest Common Factor) of Fifteen and 20, we need to factor each number (15 = 1, 3, 5, 15; 20 = 1, 2, 4, 5, 10, 20) and the most Choose the greater factor that exactly divides both Fifteen and 20, i.e. 5.

Second, which of the following number is not a factor of 21? Answer: **6** is not a factor of 21.

**What is the common factor of 21 and 30?**

The GCF of 21 and 30 is **3** . To calculate the greatest common factor of 21 and 30, we need to factor each number (21 = 1, 3, 7, 21; 30 = 1, 2, 3, 5, 6, 10, 15, 30). must be factored. And choose the greatest factor that exactly divides both 21 and 30, i.e. 3.

So what are the common factors of 20? The factors of 20 are **1, 2, 4 5, 10, 20** .

How do you make 21? We know that multiplying 1 by 21 gives 21, so they are both factors. 2 is not a factor of 21, because we cannot multiply it by any other whole number. 21.3 is a factor of 21, because it multiplies by 7 to make 21. So the factors of 21 are **1, 3, 7 and 21** .

**What are multiples of 21?**

The first 21 multiples of 10 are **21, 42, 63, 84, 105, 126, 147, 168, 189 and 210** . Every multiple of 21 is exactly divisible by 7 and appears in the table of 7, so every multiple of 21 is also a multiple of 7.

Why is 21 a prime number? Is 21 a prime number? … Numbers 21 **1, 3, 7, 21 . is divisible by** . For a number to be classified as a prime number, it must have exactly two factors. Since 21 has more than two factors, i.e. 1, 3, 7, 21, it is not a prime number.

How do you find GCF?

To find the GCF of a set of numbers, **list all the factors of each number** . The largest factor that appears in each list is the GCF. For example, to find the GCF of 6 and 15, first list all the factors of each number. Because 3 is the largest factor that appears in both lists, 3 is the GCF of 6 and 15.

What is the GCF of 21 and 35? Answer: The GCF of 21 and 35 is **7** .

**What is the fastest way to find GCF?**

What is the greatest factor of 21 and 30?

The GCF of 21 and 30 is **3** . To calculate the greatest common factor of 21 and 30, we need to factor each number (21 = 1, 3, 7, 21; 30 = 1, 2, 3, 5, 6, 10, 15, 30). must be factored. And choose the greatest factor that exactly divides both 21 and 30, i.e. 3.

How many are in 21? 21 (twenty one) is the natural number following 20 and preceding 22.

…

21 (number)

→ 20 21 22 → | |
---|---|

cardinal | twenty-one |

ordinal | 21 (twentieth) |

multiplication | 3 × 7 |

divisors | 1, 3, 7, 21 |

What are the factors of 21? **factors of 21**

- 21: Factors 1, 3, 7 and 21.
- Negative factors of 21: -1, -3, -7 and -21.
- 21: 3, prime factors of 7
- Prime factorization of 21: 3 × 7 = 3 × 7.
- The sum of the factors of 21:32.

**What is the GCF of 14 and 21?**

2 and 14 have 21 common factors, which are 1 and . are **7** . Therefore, the greatest common factor of 14 and 21 is 7.

What is the factorization of 12 and 15? The factors of 12 and 15 are **1, 2, 3, 4, 6, 12 and 1, 3, 5, 15** respectively.

What is the GCF of 10 15 and 25?

The greatest common factor (GCF) of some numbers is the largest number that is equally divisible by all numbers. For example, the GCF of 10, 15 and 25 is **5** .

What are the common factors of 21? The factors of 21 are **1, 3, 7, and 21** .

**How many factors does 15 have?**

The factors of 15 are the list of integers that can be divided equally into 15. It is the sum total of **4 factors** out of which 15 is the greatest factor and 15 has positive factors 1, 3, 5 and 15.

What is the greatest common factor of 15 and 30? Answer: The GCF of 15 and 30 is **15** .